Pat Sandra

PAHs were determined in a petroleum vacuum distillation residue using the Agilent 1290 Infinity Multiple Heart-Cutting 2D-LC solution with normal-phase in the first dimension and reversed-phase in the second dimension.

In this application the Agilent 1290 Infinity II LC was used to determine the bitter compounds iso-alpha-acids and reduced iso-alpha-acids, and the clove-like phenolic flavor 4-vinylguaiacol in bottled beer.

In this application the Agilent 1290 Infinity II LC was used to determine the bitter compounds iso-alpha-acids and reduced iso-alpha-acids, and the clove-like phenolic flavor 4-vinylguaiacol in bottled beer.

This Application Note describes the method transfer of a USP HPLC method for amlodipine besylate tablets to a UHPLC method using the Agilent 1290 Infinity II LC.

This Application Note describes the method transfer of a USP HPLC method for amlodipine besylate tablets to a UHPLC method using the Agilent 1290 Infinity II LC.

Advances in Biopharmaceutical Analysis

Analyzing Host Cell Proteins Using Off-Line Two-Dimensional Liquid Chromatography–Mass Spectrometry

With the top-selling mAbs evolving out of patent there has been a growing interest in the development of biosimilars. In demonstrating comparability to the originator product, biosimilar developers are confronted with an enormous analytical challenge. This article presents a selection of state-of-the-art analytical tools for mAb characterisation and comparability assessment.

The application of gas chromatography (GC) combined with atmospheric pressure chemical ionization mass spectrometry (GC–APCI-MS) and with supersonic molecular beam ionization mass spectrometry (GC–SMB-MS).

This article highlights some selected examples of the power of liquid chromatography combined with mass spectrometry (LC–MS) in the development of protein biopharmaceuticals.

An introduction from the guest editors of this special supplement from LCGC Europe focusing on some recent developments in pharmaceutical analysis.

The determination of genotoxic impurities (GIs) in drug substances and pharmaceutical products is an emerging topic in pharmaceutical quality control. GIs are intermediates or reactants in the synthetic pathway of a drug substance and should be monitored at ppm (?g/g drug substance) or even ppb (ng/g) levels. This is several orders of magnitude lower than in classical impurity analysis (0.05% or 500 ppm level) or in residual solvent analysis. Analytical methods for the determination of GIs include gas chromatography (GC) and liquid chromatography (LC), both often combined with mass spectrometry (MS) detection. Some typical examples of GIs trace analysis using GC and LC are presented. The potential of on-line reaction monitoring is also discussed.

Soft ionization MS using GC–APCI-MS and GC–SMB-MS offers complementary identification power for the characterization of natural products, as illustrated by the identification of alkanes, sterols, long chain alcohols, and derivatized polar compounds in tobacco leaf extracts described here.

A simple experimental setup applied in a drug discovery laboratory illustrates some anomalies and misconceptions about supercritical fluid chromatography for drug discovery.

Gas chromatography combined with atmospheric-pressure chemical ionization (APCI) was used to analyze high-molecular-weight phthalates.

Discussing the latest developments in sample preparation techniques that reduce environmental impact.

A novel and sensitive approach for analysing high-molecular-weight phthalates is described.

The second part of this series on green chromatography describes characteristics of GC and SFC

The safety of the food that our children eat is a global concern. Regulations are in place that limit the maximum level of pesticides that can be present in food meant for children, and methods to detect levels well below those limits are needed to ensure the safety of the food supply. Combining the speed and separation efficiency of ultrahigh-pressure liquid hromatography (UHPLC) with the sensitivity and selectivity of triple-quadrupole mass spectrometry (MS)-MS results in a method that can deliver ultralow quantification of pesticides in baby food, with limits of detection more than an order of magnitude below the allowed maximum levels.

Part one focusses on ways of reducing and replacing solvents commonly used as mobile phases

Pat Sandra and his team will discuss how green chromatography works in practice

This article describes methods to quantitatively analyse genotoxic and potentially genotoxic impurities in pharmaceutical ingredients

A miniature gas chromatograph incorporating a miniaturized chemical trap for enrichment, rapid thermal desorption of the trap, a resistively heated capillary column for programmed GC analysis and a micro-chip-based plasma emission detector (PED) is described. The sampling and chromatographic conditions for the analysis of volatile compounds in air are presented. The performance of the µCAD is illustrated in the universal (carbon) mode and for the selective detection of chlorinated and organo-mercury compounds. Detection limits (DLs) are at the sub-μg/L level in the carbon mode and 10 ng/L for organo-mercury compounds.

In general, polymer-based columns have a broad pH range (pH 2 to 13), and some have high temperature tolerance (up to 150°C or higher). Considerably large selectivity changes can be obtained by varying analysis temperature and mobile phase pH. Having control on these two parameters over wide ranges can be especially useful in method development.

An overview is presented of possible pathways to enhance peak capacity in liquid chromatography (LC). The peak capacity in a chromatographic separation is directly related to the plate number and thus to column length and particle size. Serial coupled columns can be used to obtain long effective column lengths, reaching over 100000 theoretical plates and peak capacities up to 900. Some theoretical considerations are made on column dimensions and particle size and examples are given of high resolution "GC-like" separations in LC using state-of-the-art LC hardware. Recent developments in LC hardware have also enhanced the applicability of two-dimensional LC–LC and comprehensive LCÃ-LC. Both techniques are extremely powerful to unravel complex samples.

When possible, GC analysis is performed under retention time locked conditions, meaning that allergen elucidation and quantification is based on mass spectral data (scan mode or specific ion detection mode) and on retention time.

An important prerequisite of a good sampling procedure for skin sebum is its reproducibility.

This article describes the pros and cons of pSFC–MS and attempts to demonstrate its broad applicability to such fields as high-throughput analysis, purity assessment, structure characterization and purification. It concludes with a look at the potential of the technique in the future of analytical drug discovery.

This column describes the principles of stir-bar sorptive extraction and presents some typical applications.